Facebook Messenger launched in 2011 as a standalone messaging app for Facebook users on iOS and Android. In 2014 Facebook removed messaging from the main Facebook app, forcing mobile users to download Messenger if they wanted to keep sending messages (on Facebook Messenger for PC or Mac, you don't need the separate messaging app).

A year later, the company started bolstering the Messenger download with added features, such as peer-to-peer payments, video calling, and business communications, including the ability to book an Uber. In 2016, Messenger added group calling, chatbots (including Facebook's own digital concierge, M), and Secret Conversations, which promise end-to-end encryption.

Messenger has exceeded 1 billion monthly active users, making it second only to Facebook-owned WhatsApp ( Windows, Mac, Android, iOS). But Messenger was late to the privacy party, only recently rolling out Secret Conversations, while lesser-known competitors had already honed their security tools, such as end-to-end encryption, the ability to conceal yourself and your activities, and deleting messages. Here are our picks for secure messaging alternatives.

Message over Signal and trust that all communications are encrypted from end to end and no data is saved. To ensure that no one takes screenshots of your messages, go to Settings, Privacy, then Enable Screen Security. There you may also tap Clear History Logs every once in a while to delete your message, attachment, and call history. If you don't believe Signal, the app's source code is available at GitHub for independent verification.

With Telegram's Secret Chat, your messages, photos, videos, and files are sent over an encrypted connection that automatically self-destructs from participating devices after receipt and cannot be forwarded. Under Settings, then Privacy and Security, you can set your Last Seen to Nobody for maximum privacy, set a Passcode Lock for when the app times out, and set up Two-Step Verification for each logon from a new device. Telegram promises never to give third parties access to your data.

Wickr Me promises that all of your communications -- audio, video, voice, and text -- are end-to-end encrypted and no metadata is kept. When you delete a message, or if it's time limited, when you set it to expire, the Secure Shredder ensures that it's irrecoverable. You can enable a password after periods of inactivity lasting from 5 seconds to a day. The unique Audio Playback setting requires a headset, so no one around you can listen in.